The palatability of pet food may be improved by an enzymatic pre-treatment of the ingredients. Reference is made to U.S Pat. No. 3,857,968 which suggests a lipase and protease treatment of fat and protein containing ingredients improving palatability, and to U.S. Pat. Nos. 4,391,829 and 4,393,085, which suggest an amylase and a protease pre-treatment of farinaceous and proteinaceous ingredients of an extruded pet food to improve the palatability thereof. Although such treatments may be employed along with practice of this invention, if desired, the discussion which follows ignores this possibility.
It is noted that research efforts toward achieving best nutritional value, improve palatability and meat-like feel in all pet food types, are within severe product cost constraints. Above all, the pet food product must remain relatively inexpensive. Appropriately enough, all pet foods contain some protein of vegetable origin, e.g., soy, corn, etc., such being a relatively inexpensive form of protein. Reference can be made to e.g., U.S. Pat. No. 3,202,514, Example 1, wherein it is indicated that 36.5% of the pet food consists of soy flakes.
Now surprisingly, according to the invention, it has been found that pet foods can be improved considerably in regard to platability and texture if the vegetable protein material component therein has been exposed to an enzymatic modification, viz a treatment with an SPS-ase preparation in aqueous medium.